Argentina will look to spring another surprise in the semi-finals against an Australia side that was pushed to the limit by Scotland last week.
Where to watch
Argentina vs Australia kicks off at 4pm BST on Sunday 25 October. Live coverage is available on ITV HD and BBC Radio 5 Live.
Since their opening game 16-26 defeat to defending champions New Zealand, there has been no stopping Argentina. While the losses of Paul O'Connell and Johnny Sexton certainly took a toll on Ireland ahead of their quarter-final meeting with the Pumas last Sunday, few predicted them to be so brutally dismantled in the manner they wer. 14-0 up with two tries in the bag within 10 minutes in Cardiff, Daniel Hourcade's side marched into the final four of the competition playing the expansive free-scoring rugby that has made them such a delight to watch. The momentum that has built has shown no sign of diminishing since bouncing back from that New Zealand defeat, something Australia may struggle to quell, having squeezed through to this stage by the skin of their teeth. When Argentina made the semi-finals of the 2007 tournament, it was a surprise. Anyone who has watched them throughout their campaign this time around knows they are fully capable of going all the way.
While their standing in world rugby will still see them enter the contests as slight favourites, the Wallabies have struggled to hit top gear in their last two games, having to survive a Welsh storm in their final pool match before needing a huge slice of fortune to defeat Scotland by a single point in last week's gripping contest. But Michael Cheika's men do have history on their side: Argentina have one just one of these fixtures in the last 10, and Australia's hopes of adding another win to their tally will have been boosted by the return of Israel Folau to the XV, who comes into replace Kurtley Beale. David Pocock, who also missed the win over Scotland, is back in the team after recovering from a knock while prop James Slipper is included, replacing Scott Sio, who is still nursing a bruised elbow suffered last weekend.
As you may have expected, Hourcade has opted for the same side that trounced Ireland last week, bar one exception: Marcelo Bosch returns to replace the suspended Matias Morini. The only other change among the Pumas ranks sees Juan Figallo take Juan Pablo Orlandi's spot on the bench.
Argentina:15 Joaquin Tuculet, 14 Santiago Cordero, 13 Marcelo Bosch, 12 Juan Martin Hernandez, 11 Juan Imhoff, 10 Nicolas Sanchez, 9 Martin Landajo, 8 Leonardo Senatore, 7 Juan Martin Fernandez Lobbe, 6 Pablo Matera, 5 Tomas Lavanini, 4 Guido Petti, 3 Ramiro Herrera, 2 Agustin Creevy (c), 1 Marcos Ayerza
Replacements:16 Julian Montoya, 17 Lucas Noguera Paz, 18 Juan Figallo, 19 Matias Alemanno, 20 Facundo Isa, 21 Tomas Cubelli, 22 Jeronimo de la Fuente, 23 Lucas Gonzalez Amorosino.
Australia: 15 Israel Folau, 14 Adam Ashley-Cooper, 13 Tevita Kuridrani, 12 Matt Giteau, 11 Drew Mitchell, 10 Bernard Foley, 9 Will Genia, 8 David Pocock, 7 Michael Hooper, 6 Scott Fardy, 5 Rob Simmons, 4 Kane Douglas, 3 Sekope Kepu, 2 Stephen Moore (c), 1 James Slipper
Replacements: 16 Tatafu Polota-Nau, 17 Toby Smith, 18 Greg Holmes, 19 Dean Mumm, 20 Ben McCalman, 21 Nick Phipps, 22 Matt Toomua, 23 Kurtley Beale
What the coaches say
Australia's Michael Cheika: "We are just right in the middle of where we need to improve massively, I feel. I still think that consistency is where the improvement is needed. So, making sure that every day at training, and every match we play, is of the highest quality in those set-pieces, and that is what our goal is.
"James [Slipper] is a leader in our squad and has performed well through this tournament so far and in the lead-up matches. This weekend is a great opportunity for the lads to improve on last week and take advantage of the chance to play on such a big stage. This weekend we want to make Australia proud of their team."
Argentina's Daniel Hourcade: "We are conscious that Australia are better than what they showed in the quarter-finals. That isn't the Australia we will face. It's going to be tremendously hard, with the breakdown the key. They took a false step – we know that the best teams remain."